The present invention relates, in general, to off-loading power from an integrated circuit device, and more particularly, to off-loading power by dissipating a portion of the power in a discrete device.
In integrated circuit applications, small surface mount packaging techniques are desirable because they provide a high packing density and a low cost alternative to large through-hole insertion packaging techniques. However, surface mount packages such as small outline integrated circuit (SOIC) packages cannot tolerate the high power dissipation required in some applications, e.g., automotive voltage regulators. Large drive current and large battery voltage excursions, which are common in automotive applications, require that the circuits have high power dissipation capabilities to accommodate the large voltage excursions.
Single in-line packaging (SIP) techniques are commonly used to meet the high power dissipation capability requirements. Compared with SOIC packages, SIPs are expensive and occupy large areas on circuit boards. Forced air cooling or liquid cooling also increase the power dissipation tolerance of a device, but they are expensive and inconvenient. Another technique for increasing the power dissipation capability of a voltage regulator includes using a switching power supply. However, the voltage output of a switching power supply is not smooth enough for many applications.
Accordingly, it would be advantageous to have a small surface mount packaged circuit that is capable of dissipating a large amount of power. It is also desirable for the circuit to be significantly less expensive than the circuits using packages such as SIPs.